[ubuntu-cloud] Ubuntu HWE kernels on AWS?

[Brad Figg]

On Tue, Jun 16, 2015 at 10:58:28AM -0600, Ben Howard wrote:
> The HWE kernels were originally targeted for hardware enablement. The
> reason for suggesting that they are not viable for cloud use, is in
> part, because of stability, support and virtual hardware was assumed to
> be fairly static. However, we are seeing that the HWE kernels are quite
> viable in cloud, that the assumption of static hypervisors was false,
> and that people need newer kernel features on older userlands (Docker,
> cgroups, file systems, etc).
> 
> By default GCE, Azure, and VMware Air, use the HWE enablement kernels at
> the request of the Clouds. Incidentally, I am in the process of
> releasing HWE builds for Trusty in the upstream images [1]. I expect to
> have AWS EC2 image availability later this week.
> 
> The biggest problem with HWE kernels is that they have a shorter life
> cycle (i.e. 14.04's hwe-{u,v,w} series will only live for 9 months). So
> if you elect to use an HWE kernel, be aware that you may have to switch
> off of it later to get bug fixes.

This is not correct. An HWE kernel is supported until the first point
release of the next LTS. That "next" LTS kernel becomes the last and only
supported HWE kernel for the current LTS for the remaining length of
support for the current LTS.

Please see:
    https://wiki.ubuntu.com/Kernel/LTSEnablementStack

> 
> For 12.04, linux-image-generic-lts-trusty is supported for the remaining
> life of 12.04. The generic kernel is -virtual with a larger set of
> modules; it is fine to install on virtual targets.
> 
> For 14.04, linux-image-hwe-virtual-trusty will pull in the latest
> supported hwe-kernel (and auto-upgrade you).
> 
> ~Ben
> 
> [1] https://cloud-images.ubuntu.com/trusty
> 
> On 06/16/2015 08:42 AM, Peter Wolanin wrote:
> >
> > Ubuntu offers package for 12.04 like linux-image-3.13.0-55-generic
> > 3.13.0-55.92~precise1 that upgrade the kernel version.
> >
> > However, this wiki page says these kernels should not be used for
> > Cloud deployments:
> > https://wiki.ubuntu.com/Kernel/LTSEnablementStack
> >
> > I also note that there is no -virtual version of the kernel upgrade
> > package.
> >
> > Is that note overly cautious, or are there real risks in trying to
> > switch to the upgraded kernel?  We are motivated by fixes for xfs
> > problems we are seeing when using the default 12.04 kernel on AWS.
> >
> > Thanks,
> >
> > -Peter
> >
> > -- 
> > Peter M. Wolanin, Ph.D.      : Momentum Specialist,  Acquia. Inc.
> > peter.wolanin at acquia.com <mailto:peter.wolanin at acquia.com> : 609-235-6869
> >
> >
> 
> -- 
> 
> 
> Ben Howard
> ben.howard at canonical.com
> Canonical
> GPG ID 0x5406A866
> 
> 
> 



> -- 
> Ubuntu-cloud mailing list
> Ubuntu-cloud at lists.ubuntu.com
> Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-cloud

Brad
-- 
Brad Figg brad.figg at canonical.com http://www.canonical.com